The objective of this project is to determine those factors that control blood flow to the uterus. This includes elucidation of physiologic control mechanisms in non-pregnant and pregnant uteri and determination of the effects of pathologic stimuli and pharmacologic agents on the uterine vasculatures. Uterine blood flow will be measured with electromagnetic flowmeters and differential reactitity of the vasculatures will be determined by isotope-labelled microspheres. Glycosaminoglycan content will be evaluated in non-pregnant and gravid uterine tissues.